Answer:
A) $38,650; 48.31%
Step-by-step explanation:
The computation of the contribution margin and the contribution margin ratio is shown below:
Contribution margin = Service Revenue - Cleaning Supplies Used - wages expense
= $80,000 - $22,000 - $19,350
= $38,650
The variable cost is Cleaning Supplies Used + wages expense
And, the contribution margin ratio equals to
= (Contribution margin ÷ sales) × 100
= ($38,650 ÷ $80,000) × 100
= 48.31%